When people are dizzy, they are often sent to a vestibular audiologist for a vestibular evaluation. The vestibular system is the balance part of the inner ear. A comprehensive vestibular evaluation is used to determine where the balance issue is occurring. The first thing you will realize when scheduling for a vestibular evaluation is the amount of time for the appointment. Many vestibular clinics will schedule anywhere from 2 to 3 hours for a vestibular evaluation. There are many tests included in the full battery to provide comprehensive information about the full vestibular system. Some of the tests are used to evaluate central function while others will evaluate peripheral vestibular function. At some clinics, you will see both an audiologist and a physical therapist or one or the other.
There are certain tests that can only be done by an audiologist; although, some vestibular testing can be done by an audiologist or physical therapist. Both types of professionals have extra training specifically in the vestibular system. The tests performed by an audiologist are mostly specific to the ears. Many times a basic hearing test is required to ensure the hearing part of the inner ear is functioning correctly and to rule out any issues that could indicate a balance disorder.
Many tests with an audiologist are done in the dark. Videonystagmography or VNG is testing done while wearing video goggles. Audiologists are able to test the inner ears by tracking eye movements. So while wearing goggles, the audiologist might have you watch specific things on a screen or move your head in a specific way. Caloric testing is another test of the inner ear balance system that is usually the most provoking of dizziness that people experience. The audiologist uses air, or sometimes water to change the temperature of the fluid in the inner ear to stimulate the vestibular system. Often times, the patient will feel like they are spinning slightly or drifting to one side; however, it is important to know that the audiologist is in complete control of the manipulation of the inner ear and can make the dizziness stop at any time. As soon as the ear fluid returns to its natural body temperature, the dizziness stops. They will typically do a warm temperature and a cool temperature in each ear for this test.
VEMP testing is another test that requires specific head movements while listening to clicks. This test does not typically evoke dizziness. With specific head movements and measuring electrical brain activity, we are able to measure a different part of the vestibular system. The audiologist may perform an Auditory Brainstem Response (ABR) or Electrocochleography (ECochG) to further investigate electrical potentials depending on the patient's medical history or symptom presentation.
If there is a vestibular dysfunction that can be treated, likely the audiologist or physical therapist can treat the same day or within a week. Vestibular rehabilitation might also be recommended. A referral to neurology, cardiology, primary care, or otolaryngology may also be warranted depending on the diagnosis.